1. Field
Example embodiments generally relate to fuel assembly components attachable to fuel structures in nuclear power plants.
2. Description of Related Art
Generally, nuclear power plants include a reactor core having fuel arranged therein to produce power by nuclear fission. A common design in U.S. nuclear power plants is to arrange fuel in a plurality of fuel rods bound together as a fuel assembly, or fuel bundle, placed within the reactor core. These fuel rods typically include several elements joining the fuel rods to assembly components at various axial locations throughout the assembly.
As shown in FIG. 1, a conventional fuel bundle 10 of a nuclear reactor, such as a BWR, may include an outer channel 12 surrounding an upper tie plate 14 and a lower tie plate 16. A plurality of full-length fuel rods 18 and/or partial length fuel rods 19 may be arranged in a matrix within the fuel bundle 10 and pass through a plurality of spacers 20. Fuel rods 18 and 19 generally originate and terminate at upper and lower tie plates 14 and 16, continuously running the length of the fuel bundle 10, with the exception of partial length rods 19, which all terminate at a lower vertical position from the full length rods 18.
As shown in FIG. 2, fuel elements 25 may be shaped in pellet-form and placed within the fuel rods 18 or 19. These fuel pellets 25 may be “stacked” within the fuel rod continuously to provide fuel through the length of the fuel rod 18 or 19. The stacking of fuel pellets 25 may permit expansion or other deformation of the fuel pellets 25 during the operation cycle of the reactor core.
In conventional practice, entire fuel rods are removed from the nuclear fuel rod assemblies in order to monitor materials performance. For example, a fuel rod that has been in situ in a BWR is removed and/or retrieved from the fuel rod assembly and moved to a hotcell examination facility. At the hotcell examination facility, the fuel rod is examined to determine such parameters as oxide thickness to determine levels of corrosion and hydrogen content achieved during reactor operation. Another method referred to as “shaving” has been suggested to monitor materials performance of fuel rods. In shaving, a portion of the outer surface of a fuel rod is “shaved” or removed and the hydrogen content of the shavings is then determined. Alternatively, entire spacers and/or water rods may be retrieved and examined. However, all of these methods of monitoring materials performance require substantial effort, are costly, and may create waste that requires substantially more effort to handle and process.